Process of treating iron and steel.



W. F. M. MOGARTY. PROCESS OF TREATING IRON AND STEEL.

APPLIUATION FILED MAR. 6, 1908.

13 546 Patented Oct. 20, 1908,

lwwzntoa UNITED srArus ratrnnr orrron WILLIAM F. MASON MCGARTY, OF ROCKY RIDGE, MARYLAND, ASSIGNOR'OF ONE-FOURTH TO GEORGE O. EATON, ONE-FOURTH TO THOMAS M. AOKEN, AND ONE-THIRTIETH TO ALEX: ANDER J. GUTTMAN, OF NEW YORK, N. Y.

PIRDCESS OF TREATING IRON AND STEEL.

Specification of.Letters Patent.

Patented- Oct. 20, 1908.

Original application filed November 23, 1907, Serial. No. 03,452. Divided and this application filed March 6. 1908.

' Serial No. 419,573.

To all whom it may concern:

Be it known that 1, WILLIAM F. MAsoN MCCARTY, a citizen of the United States, re-

siding at Rocky Ridge, in the county of Fredcrick and State of Maryland, have invented certain new and useful Improvements in Processes of Treating Iron and Steel, of which the following is a specification.

This invention relates to processes of treating iron and steel, and particularly steel, to produce therefrom ingots which are free, or practically free, not only from sulfur and phosphorus but also from the occluded or otherwise held gases which cause fissures, blow holes and like structural flaws in molded metal.

An important advantage of my invention resides in the fact that, in the practice of my process, cyanogen, which exercises a highly deleterious effect upon steel, is practically wholly eliminated. v

A further important advantage of my invention is that it is adapted to the treatment of metals or ores containing titanium or metals pf like character, which are injurious to stee In accomplishing the purposes of my invention I add to the materials from which the metal is produced or to the metal after reduction, certain reagents which, by their reaction upon the impurities, under the con ditions of the processes hereinafter set forth, effect the elimination thereof.

I have discovered that the contaminating impurities hereinbefore referred to, can be, to a great extent, removed by adding to the ore, or to the reduced. metal one, or more chloride decomposable at the temperature of molten iron, preferably a mixture of calcium chlorid (CaOl and sodium chlorid (NaCl) and blowing. superheated steam or superheated steam and air through the molten metal, or subjecting it, while in a molten condition, to the action of a vacuum. I have also discovered that, by using the above mentioned reagents and blowing superheated steam or superheated steam and air through the molten metal, the impurities of the latter may be eliminated to an extent hitherto unobtainable, if such treatment is combined with or followed by the subjection of the metal to the action of a vacuum;

In carrying out my process in its preferred form, I add to an average grade of ore or to the molten iron or steel therefrom, approximately 25 pounds of calcium chlorid and 100 pounds of sodium chl'orid to every ton of metal or to the ores from which this amount of metal may be reduced, the reduction of the ore being carried out in accordance with the usual practice in the art. The amount of chlorid or chloride to be added depends upon the character of the ore or metal treated. A determination of the nature and amount of impurities will enable a steel worker of some experience in using my process, to determine with fair accuracy just the amount of salts to be added.

If the metal has been produced in an ordinary'blzist-firrnace it must be transferred to a Bessemer converter, provided with a vacu um pump attachment of the character indi cated in the accompanying drawing. It is advisable however, toem loy a blast furnace in which the metal may a so berefined; such a furnace being illustrated in the drawing referred to.

After the addition of the calcium chlorid and sodium chlorid, superheated steam is blown through. the metal, preferably in rapidly occurring intermittent jets, or air and superheated steam are alternately passed through the liquid metal and the latter is subjected to the action of a vacuum. The vacuum treatment may follow the injection of the steam or air and steam or the exhaust pump may be started when the steam or air and steam is turned on.

The treatment with steam and vacuum is continued until a test of the metal. shows it tobe freed from its impurities. A little more experience in treating iron and steel from a certain source will render it possible to determine the proper .duration of the treatment with practical certainty.

l/Vhile the conditions under which the reactions occur are such as to render it impossible to fully determine the exact chemical reactions which occur in the practice of my process, it a )pears that the treatment with one or more'c lorids and particularly chlorids of calcium and sodium, particularly where superheated steam is injected, causes a reaction of dissociated chlorm with the sulfur,

- practice of my phosphorus and the difficultly removable readily removed therefrom, particularly by the action of a vacuum.

The treatment is particularly noteworthy in' that cyanogen contained in the molten metal, is decomposed with the formation of ammonia, 'which is particularly readily removed by the action of a vacuum.

In treating metals or ores containing titanium or similar impurity, thelatter forms compounds, with, it is thought, the chlorin and cyanogen present, which are readily removed by volatilization from the material treated. I

In the practice of my process I may advantageously employ the novel form of furnace shown in vertical section in the accompanying drawing, although may process may be carried out practically and successfully, although not so advantageously, in other forms of furnaces or converters.

In the drawing 1 represents a furnace providedwith a crucible 2 into which twyers 3 and 4 are arranged to discharge'air and superheated steam respectively. Cocks 5 and 6 are provided to control the supply of air and steam. An outlet 7, adapted to be closed by a fire clay plug is provided in the crucible The body of the furnace. is provided throu bout the greater portion of its len th with ouble walls 8 and) as illustrated. he inner walldepends from the upper solid portion of the furnace wall and terminates in an open lower end 10 which is of annular shape and of reduced diameter, the said end extending down into the crucible 2 to a point below the level of the molten metal, whichwill be contained therein during the use of the furnace.

Between the inner and outer walls of the furnace is an annular chamber 11 which is in communication with the crucible 2. The chamber 11 is connected with the interior of the furnace by numerous openings 12 arran ed in the walls, above the melting zone.

T e furnace is supplied with a cover 13 which forms a substantially air tight joint with the topof the furnace.

Adjacent the top of the furnace I provide a pipe 14 which is connected with a powerful exhaust pump, (not shown) by which air and the gases arising from the. metal treated may be withdrawn, in the treatment of the metal as hereinbefore referred to. ,A brick-work su port 15 may also be provided.

n the use of the furnace, in the preferred rocess, it is charged with ore, flux and fue with the addition of calare not of a nacorms cium and sodium chloride, before mentioned, and the charge treated in accordance with the usual practice in the operation of blast furnaces. When the ore has been reduced, the metal in the crucible 2 is subjected to the treatment with superheated steam or air and superheated steam and the vacuum pump set in operation to withdraw air and gases through the pipe 14, as has been hereinbefore fully described.

It will be noted that, inasmuch as the chamber 11 and openings 12 provide a passage for the steam or air and steam, w iich has passed through the metal in crucible 2, it is not necessary to force or draw the entire body ofsteam or air and steam injected into the metal, through the mass remaining in the body of the furnace.

1 have not claimed herein the furnace which I have shown and described, as this invention will form the subject matter of a separate application which is now being preparerb Metal treated by my process will be found to be practically wholly free from impurities, to have a close fibrous or lamellar structure, be wholly free from fissures, flaws, seams, blow holes and the like, and to be possessed of great ductility, malleability and tensile strength.

It is to be understood that known e uiv alents of the materials and ste s herein efore recited may be employed wit rout departing derstood that the treated metal may, without departing from my process, be withdrawn from the furnace into a mold, by and under the action of a vacuum, as fully described in my copending application for a method of producing ingots free from blowholes, filed July 12, 1907, Serial Number 382,488.

' The process hereiifafter claimed is described but not claimed in an application filed by me on November 23, 1907, Serial No. 403,452 of which this application is a division.

Having thus described my invention, I claim:

1. A process of purifying iron and steel which consists in incor orating sodium chlorid and calcium chlori therein and subjecting the metal, in a molten state, to the action of superheated steam.

v2. A process of purifying iron and steel which consists in incorporating therein sodium chlorid and calcium chlorid, in the a proximate proportions of 100 pounds of t e ormer and 25 pounds of thelatter, to every ton of metal and subjecting the metal, in a rid and calcium chlori therein and subject ing the metal, in a molten state, to the-action of superheated steam and a vacuum.

5. A process of purifying ironand steel which consists in incor orating sodium chlo rid and calcium chlori therein' and subjecting the metal, in a molten state, to the action of superheated steam in intermittent im-' pulses and to the action of a vacuum.

6. A process of purifying iron and steel which consists in incorporating sodium chlorid and calcium chlorid therein, passing superheated steam through the metal and then subjecting it to the action of a vacuum.

7. A process of purifying iron and steel which consists in incor crating sodium chlorid and calcium chloriil therein, passing superheated steam in intermittent jets or imulses through the metal and then subjecting it to the action of a vacuum.

8. A process of purifying iron and steel which consists in incorporating sodium chlorid and calcium'chlorid therein, passing superheated steam and air through the metal and then subjecting it to the action of a vacuum.

,9. A process of" purifying iron and steel which consists in incorporating sodium chlorid and calcium chlorid therein, passing superheated steam, in intermittent jets or impulses and air throughthe metal and then subjecting it to the actionof a vacuum.

10. .A process of purifying iron and steel which consists in incorporating therein, so-

dium chlorid and calcium chlorid in the approximate proportions of 100 pounds of the former and 25 pounds of the latter to every ton of metal, passing superheated steam through the metal and then subjecting it to the action of a vacuum.

11. A process of purifying iron and steel which consists in incorporating therein, so

dium chlorid and calciumchlorid in the proximate proportions of 100 pounds of former and 25 pounds of the latter to'every ton of metal, passing superheated steam-1n intermittent jets or impulses through the metal and then subjecting it to the action of a vacuum. I

12. A process of purifying iron and steel which consists in incorporating therein, so dium chlorid and calcium chlorid in the approximate proportions of 100 pounds of the former and 25 pounds of the latter to every I ton of metal, passing su erheated steam in intermittent ets 01' im u ses and air through the metaland then sub ecting it to the action of a vacuum.

In testimony whereof I ai'fix my signature in presence of two witnesses.

WILLIAM F. MASON MGCARTY. Witnesses:

SIGMUND J. BLOCK, C. L. PARKER. 

